Tectonic Therapeutic is a clinical-stage biotech focused on discovering and developing biologic drugs — proteins and antibodies — that target G-protein coupled receptors (GPCRs), a class of cell-surface receptors that regulate blood pressure, cardiac function, and immune response. Tectonic's lead asset, TX45, is an engineered Fc-relaxin fusion molecule that mimics the vasodilatory and anti-fibrotic effects of the naturally occurring hormone relaxin, but with a far longer half-life that makes it viable as a therapeutic. TX45 is being developed primarily for pulmonary hypertension in the setting of heart failure with preserved ejection fraction (PH-HFpEF), a chronic condition with no FDA-approved treatments. TX45 has shown encouraging Phase 1 results, and Tectonic is running a Phase 2 trial with topline results expected in 2026. Tectonic's second candidate, TX2100, is an antibody targeting the APJ receptor, in development for hereditary hemorrhagic telangiectasia (HHT), a rare genetic bleeding disorder with no approved therapies. TX2100 entered Phase 1 trials in early 2026. Underlying both programs is Tectonic's proprietary GEODe platform, originally developed at Harvard and licensed to Tectonic in 2022, which engineers GPCRs into stable conformations suitable for antibody discovery. Tectonic has no approved products or revenue, funds operations through equity financing, and outsources manufacturing to CDMOs.